The invention relates to an arrangement for bi-axial tiltable rotary support of a load rotor, such as an antenna, a plane mirror or the like for transmission/reception of electromagnetic radiation, in a projectile which during firing is exposed to large acceleration forces, such that the rotatable body can perform limited tilting or turning motions around two mutually perpendicular tilt axes lying in a plane which is substantially perpendicular to the longitudinal axis of the projectile, while the rotation axis of the body substantially coincides with the longitudinal axis of the projectile.
The rotor or rotatable body may as mentioned be an antenna, a plane mirror or the like, which can be included in a target tracking device and, after discovery of a target, adapted to be locked onto the target, whereafter the tracking device guides the projectile towards the target. During the search phase of this guiding procedure the antenna is caused to perform a scanning motion, for example a conical scanning, and for this purpose it must be tiltable around two mutually perpendicular axis. The rotation of the antenna then can have for its purpose, if the antenna axis is somewhat oblique relative to the rotation axis, to increase the chances for discovery of a target by increasing the effective illumination area. In certain systems a gyroscope is included, the rotor of which serves as a mirror for electro-magnetic radiation. Also in this case it is required that the body serving as rotor/mirror is bi-axially supported with an angular transducer arranged at each tilt axis. A common bi-axial support is the gimble support comprising two gimbal rings mounted in each other and each rotatable about its tilt axis, the inner ring supporting the rotatable body.
A special problem appearing in the case of journalling a body in a projectile is that the body and thereby the support is exposed to extremely high acceration forces, both axially and radially; the radical force due to the rotation in the fire tube. These forces are combined to a resulting force vector, which is directed in an indefinite angle obliquely backwards and which rotates together with the projectile. These circumstances in combination with the high acceleration forces involved have the effect that a gimbal support of known type cannot be used.
The object of invention is to produce a support which can withstand such extremely high acceleration forces composed of an axial and a radical component, which appear at the firing of a projectile, and which support is suitable both as supporting arrangement for a scanning antenna or reflector included in a target tracking device and of a rotor included in a gyroscope.